Stanley Morison argues in Politics and Script that the nineteenth-century invention of the sans serif lowercase was no less than ‘the most novel and permanent contribution to letter-design that has appeared on the printed page since the Aldine Italic of 1501’. Given that the sans serif has become the dominant typographic form of the past century (for all but lengthy text setting, and sometimes even for that too), it is more than a little surprising that its early development in the century prior — from a brutish all-caps poster style into a viable upper- and lowercase text style — has scarcely been studied or documented. This talk will trace its evolution as uncovered to date by a primary-source research project in progress.